Figure 5.

Resveratrol attenuates copper-induced immunoglobulin-binding protein (BiP) upregulation but has no effect on eukaryotic translation initiation factor 2 (eIF2) phosphorylation or heat shock protein 90 (HSP90) and HSP70 expression. (a) Phosphorylated eIF2 (p-eIF2) and (b) BiP, HSP90, and HSP70 relative protein levels were determined by western blot 72 h after the removal of 350 μM CuSO₄ (or Na₂SO₄, for controls) in fibroblasts that were allowed to recover in the presence or absence of resveratrol (5 or 10 μM). Representative blots are depicted and densitometric quantification is plotted with the assumption that the protein level of each analyzed protein in control cells without resveratrol equaled 1. Ponceau S staining was used to normalize protein loading. Data are presented as means ± SEM of at least three independent experiments. ^∗∗p < 0.01; ^∗∗∗p < 0.001; and ^nsnonsignificant, for the comparisons between the indicated groups.